Method of sharpening endless slicer blades



Dec. 6, 1955 HlLL METHOD OF SHARPENING ENDLESS SLICER BLADES Filed April28, 1952 mu m Nn T M A r 0 GM M m United States Patent METHOD OF'SHARPENING ENDLESS SLICER BLADES Gordon Hill, Bettendorf, Iowa,assignor, by mesne assignments, to Bettendorf Bakery Equipment Qompany,Bettendorf, Iowa, a corporation of Iowa Application April 28, 1952,Serial No. 284,741

2 Claims. (Cl. 51-285) This invention relates to a method of sharpeningendless slicer blades in place in a bread slicing machine and has forits object to provide a method by means of which the band blades of abread slicing machine may be quickly and easily sharpened withoutremoving them from the machine.

Endless band blade bread slicing machines are commonly provided withvertically spaced pulleys over which the bands run and intermediate thepulleys they have one or more transverse rows of blade guides forholding the blades in parallel planes and equally spaced apart in theslicing zone. Usually two vertically spaced rows of blade guides areprovided, one above and the other below a slicing zone so that theblades are held parallel and against relative lateral movements whilepassing through the bread.

The present invention provides a method of sharpening the blades of abread slicing machine while the machine is running at operating speed byinserting a small diameter cylindrical grinding wheel between the bladesadjacent one of the rows of blade guides and preferably in the slicingzone between the upper and lower sets of guides while the machine isrunning at operating speed, driving the grinding wheel and engaging itwith the cutting edge of the adjacent blade that is traveling in thedirection opposite that of the blade engaging portion of the grindingwheel so that the relative speeds of travel of the abrasive surface andblade is the sum of the peripheral speed of the grinding wheel and thelinear speed of the blade. The speed of rotation of the grinding wheelis such that the speed of its periphery relative to the work issufiicient to obtain effective grinding action.

In order to elfectively grind both sides of the cutting edges of theblades, the direction of the grinding wheel is reversed when it isshifted from one side of the blade to the other to provide properrelative travel of the abrasive surface with respect to the blade.

In order to conveniently position the grinding wheel with respect toeach of the band blades, a combined guard and tool rest is providedwhich has equally spaced concave tool seats the centers of which arealined with the cutting edges of each of the band blades.

The grinding operation is preferably performed with a portable grindingunit which comprises a small reversible electric motor having a grindingwheel attached to its shaft. The motor housing is of a size to provide aconvenient hand grip and has an end portion adapted for engagement inthe concave seats of the tool rest so that the grinding wheel can befirmly held in proper position with respect to each of the band blades.

Reference should be had to the accompanying drawings forming a part ofthis specification, in which:

Figure l is a fragmentary perspective view showing the combined guardand tool rest in place on the feed bed of a slicing machine, with thegrinding unit positioned for grinding one side of a cutting edge of oneof the band blades;

Fig. 2 is a fragmentary side elevation of the machine with the combinedguard and tool rest in place thereon;

Fig. 3 is a front elevation of the combined guard and tool rest;

Fig. 4 is a vertical section taken on the line indicated at 44 in Fig.3;

Fig. 5 is a fragmentary sectional view showing the grinding wheel inengagement with the blade; and

Fig. 6 is a fragmentary side elevation of a cutter blade.

in the accompanying drawings a bread slicing machine is showndiagrammatically, the machine having upper and lower pulleys 1 and 2,the lower of which is driven by suitable means such as a motor 3. Aseries of band blades 4 run over the pulleys 1 and 2 and are crossedbetween the pulleys. Upper and lower sets of adjustable blade guides 5and 6 are provided above and below the crossing zone. The upper andlower rows of blade guides serve to hold the portions of the bladesbetween the guides in parallel planes and equally spaced. Bread to besliced is fed between the upper and lower guides 5 and 6 and is advancedthrough the slicing zone on a feed bed 7 the top surface of which is inthe plane of the top surfaces of the blade guides 6. The bread is fed tothe blades by means of a feed conveyor 8 and the sliced loaves pass fromthe slicer to a delivery conveyor 9.

The blade adjusting and guiding means and the means for guiding thebread into the slicer are not described in detail since these featuresare well known in the art. For example, the slicing machine may beconstructed in accordance with the disclosure of the patent to Kottmannet al. 2,297,710, October 6, 1942.

As shown in Fig. 5, the guide members are provided with narrow slots 1tthrough which the blades pass, which serve to hold the blades inparallel planes in the slicing zone. To sharpen the blades 4 withoutremoving them from the machine the bread guides associated with the bed7 are removed and a combined guard and tool rest 11 is mounted on thebed. The guard 11 is disposed in front of the band blades facing thecutting edges thereof and parallel to the row of band guides 6. Forsecuring the combined guard and tool rest 11 in place on the bed 7, itis provided with attaching brackets 12 which have hooks 13 that engagewith the bed 7 at the edge of a slot 14 in the bed through which theflights of the feed conveyor 3 pass. The brackets 12 rest on the topface of the bed 7 and serve to position the guard 11 with respect to theslicer blades. The guard 11 is provided with a longitudinal slot 15through which access to the blades is provided for a suitable grindingtool, and the bottom edge of the slot 15 is formed to provide regularlyspaced concave seats 16. The spacing of the seats 16 is such that theband blades may be adjusted to aline a portion of the cutting edge ofeach with the central portion of one of the seats 16.

The grinding operation is performed with a grinding wheel 17 ofcylindrical form and of small diameter. The grinding wheel 17 isdetachably secured to the shaft of a small reversible electric motor 18,the motor 18 and grinding wheel 17 forming a portable grinding unitwhich can be easily manipulated to bring the grinding wheel intoengagement with the individual band blades.

In order to enable the operator to hold the grinding wheel in properposition during the grinding operation, the housing of the motor 18 isof a size suitable to provide a hand grip and is formed to provide atubular end portion 19 which is adapted to rest in any one of theconcave seats 16 of the tool rest and a shoulder 20 engageable with theouter face of the tool rest to limit the inward movement of the grindingwheel.

To grind the band blades of the slicing machine the bread guides areremoved and the combined guard and tool rest 11 is secured in place onthe feed bed 7 as shown in Fig. 1. The feed conveyor 8 is disconnectedfrom its driving means and the motor 3 is operated to drive the bandblades 4 at the speed at which they are normally driven during operationof the slicing machine. The grinding unit is then positioned with theextension 19 of the motor housing in engagement with one of the seats 16of the tool rest and with the grinding wheel 17 beside the cutting edgeof the blade that is alined with the seat upon which the extension 19rests.

The grinding wheel may be initially positioned either to the right or tothe left of the blade to be ground but the motor 18 will always beoperated to drive the grinding wheel in the direction in which theportion of its periphery which is to engage the blade will move in adirection opposite that in which the blade with which it is to engage ismoving. After the grinding wheel 17 has been positioned and after themotor 18 has been started in the proper direction, the grinding unit maybe rocked on the seat 16 with which it engages to bring the grindingwheel to its grinding position where it engages the blade as shown inFig. of the drawing. By successively engaging the grinding wheel withthe edges of the band blades moving past the tool rest all of the bladesof the slicing machine can be quickly and easily sharpened withoutremoving them from the machine.

In order to avoid frequent starting and stopping of the grinding wheeldriving motor, the blades are preferably all ground on one side bypositioning the grinding unit on successive seats with the grindingwheel to the right or to the left of the successive blades while thegrinding wheel is being driven in the proper direction for grinding theblades to which the wheel is presented, after which the direction ofrotation of the grinding wheel is reversed and the blades are ground ontheir opposite sides.

The grinding wheel must be of small diameter in order to enable it to beinserted between the blades of the slicing machine and because of itssmall diameter a high speed of rotation is required to obtain a linearspeed of its periphery sufficient for efficient grinding action. By socontrolling the operation of the grinding wheel that its peripheralblade engaging portion travels in a direction opposite that of the bladewith which it engages, the speed of the abrasive surface of the wheelwith respect to the blade with which it engages is greatly increased,making it possible to obtain rapid grinding action with a motor drivengrinding wheel of a diameter small enough to be received between theadjacent band blades of a bread slicing machine.

In slicing machines in which the band blades are crossed the grindingwheel may be positioned between corresponding runs of adjacent bandswhich are spaced apart double the thickness of the slices to be cut andK which have their cutting edges close to the tool rest 11. The grindingwheel receiving space is twice the thickness of the slices to be cut,usually about one inch, and the grinding wheel may be of any size thatwill permit it to be conveniently manipulated.

The tubular portion 19 is slidable on the seats 16 of the tool rest, sothat the grinding wheel 1.7 may be adjusted inwardly or outwardly withrespect to the tool rest to engage different portions of the peripheryof the grinding wheel with the band blades so that wear on the grindingwheel may be uniformly distributed and the wheel may be used longerbefore it is necessary to clean it.

Because of the rapid travel of the blades with respect to the grindingwheel, only a short period of time is required to sharpen each of theblades.

It is to be understood that in accordance with the provisions of thepatent statutes, variations and modifications of the specific devicesherein shownand described may be made without departing from the spiritof the invention.

What I claim is:

1. The herein described method of sharpening an endless band blade inplace in a bread slicing machine that has a plurality of endless bandblades and regularly spaced parallel guides that hold the blades inparallel planes in the slicing zone which comprises driving said slicingmachine at its operating speed, inserting a cylindrical grinding wheelhaving a diameter less than the width of the space between said bladeand the next adjacent blade on one side thereof into said space nearsaid guides, driving said grinding wheel in the direction in which theperipheral portion thereof adjacent said blade moves in a directionopposite that of said blade, moving said grinding wheel laterally toengage a portion of its periphery with the adjacent side of the cuttingedge of said blade, holding said grinding wheel in engagement with saidblade with its axis at a small angle to the plane of said blade,disengaging the grinding wheel, reversing the direction of rotation ofthe wheel and applying the wheel to the opposite side of the cuttingedge of said blade with its axis disposed at a reverse inclination withrespect to the plane of said blade.

2. The herein described method of sharpening a sealloped endless bandcutter blade in place in a bread slicing machine that has spacedpulleys, a series of scalloped endless slicer blades running over saidpulleys and crossed between said pulleys, and a row of blade guidesextending transversely of the blades intermediate said pulleys forholding the portions of said blades adjacent said guides in regularlyspaced parallel planes which comprises: driving said pulleys and theblade carried thereby at their operating speed, inserting a cylindricalgrinding wheel having a diameter less than twice the distance betweensaid adjacent parallel planes into the space between one of saidscalloped blades and the next adjacent blade on one side thereof,driving said grinding wheel in the direction in which the peripheralportion thereof adjacent said blade moves in a direction opposite thatof said blade, moving said grinding wheel laterally to engage a portionof its periphery with the adjacent side of the cutting edge of saidscalloped blade, holding said grinding wheel in engagement with saidblade with its axis at a small angle to said parallel planes,disengaging the grinding wheel, reversing the direction of rotation ofthe wheel, and applying the wheel to the opposite side of the cuttingedge of said scalloped blade with its axis disposed at a reverseinclination with respect to said parallel planes.

References Cited in the file of this patent UNITED STATES PATENTS396,553 Fowle Jan. 22, 1889 1,520,817 Harris Dec. 3.0, 1924 1,551,167Orlow Aug. 25, 1925 1,706,483 Corbett Mar. 26, 1929 1,911,974 SheltonMay 30, 1933 1,963,449 Rubin June 19, 1934 1,981,944 Brostrom Nov. 27,1934 2,002,812 Hansen May 28, 1935 2,073,861 Wolf Mar. 16, 19372,148,457 Grossarth Feb. 28, 1939 2,225,600 Kottmann Dec. 17, 19402,621,454 Callahan Dec. 1.6, 1952

